A typical conventional beverage serving apparatus in which a beverage such as coffee is extracted from a raw material such as coffee beans so as to be served in a cup is shown in FIG. 1. The beverage serving apparatus shown in FIG. 1 consists of water supply unit 100A and beverage preparation unit 100B.
Water supply unit 100A is provided with reservoir 101 for storing tap water, water supply pump 102 for transporting the water stored in reservoir 101 under pressure through water supply tubes 102A and 102B, cold water tank 103 storing cold water for cooling the water flowing in water supply tube 102A, cold water supply valve 104 for discharging the cold water cooled in cold water tank 103 in accordance with a serving command for cold syrup juice, hot water tank 105 for heating the water supplied thereto through water supply tube 102B and storing the hot water thus obtained, hot water supply valve 106A for supplying the water stored in hot water tank 105 to hot water supply tube 107A in accordance with a serving command for regular coffee, hot water supply valve 106B for supplying the water stored in hot water tank 105 to hot water supply tube 107B in accordance with a serving command for instant coffee, and re-heating heater block 108 for heating again the hot water flowing in hot water supply tubes 107A and 107B.
Tap water is supplied to reservoir 101 from water supply tube 101b through water supply valve 101a. The water stored in reservoir 101 passes, on the one hand, through water supply tube 102A having cold water supply valve 104 thereon so as to be discharged out of cold water-supplying nozzle 104A and, on the other hand, through water supply tube 102B having water supply valve 102C thereon to hot water tank 105. The cold water cooled in cold water tank 103 is discharged out of cold water-supplying nozzle 104A at an end of water supply tube 102A. Hot water tank 105 is provided with heater 105A for heating the water in the tank to a temperature not lower than a predetermined temperature (for example, 95).
Beverage preparation unit 100B is provided with regular coffee canister 109 for storing the powdered raw material (raw material, hereinbelow) for regular coffee to be supplied to beverage extraction unit 100C (explained below) ; raw material chute 110 for receiving the raw material for regular coffee; beverage extraction unit 100C for mixing the raw material and hot water supplied from hot water supply tube 107B and extracting regular coffee to be supplied to beverage supply tube 22C; sugar canister 111 for storing sugar to be supplied to raw material chute 114; instant coffee canister 112 for storing powdered instant coffee to be supplied to raw material chute 114; milk canister 113 for storing milk to be supplied to raw material chute 114; raw material chute 114 for receiving sugar, instant coffee and milk to be supplied to mixing bowl 115 (explained below); mixing bowl 115 for mixing sugar, milk, raw material and hot water to prepare coffee to be served; cup supply apparatus 116 for storing and supplying cups C; cup receiver 117 for receiving cup C supplied from cup supply apparatus 116; waste bucket 118 for receiving and storing wastes, being placed under cup receiver 117; and steam exhaust tubes 119A and 119B having blower fan 120 at distal ends thereof, for exhaling steam produced in beverage extraction unit 100C and mixing bowl 115.
Regular coffee canister 109 has outlet 109A. The raw material stored in regular coffee canister 109 is discharged from outlet 109A and supplied to beverage extraction unit 100C by way of raw material chute 110 in accordance with a serving command for regular coffee. Sugar canister 111 has outlet 111A, from which sugar stored in sugar canister 111 is discharged from and supplied to raw material chute 114 in accordance with a serving command for regular coffee or instant coffee, either with sugar. Instant coffee canister 112 has outlet 112A, from which the raw material for instant coffee stored in instant coffee canister 112 is discharged to raw material chute 114 in accordance with a serving command for instant coffee. Milk canister 113 has outlet 113A, from which milk stored in milk canister 113 is discharged to raw material chute 114 in accordance with a serving command for regular coffee or instant coffee, either with milk.
Mixing bowl 115 has nozzle 115A. Regular coffee supplied from beverage supply tube 22C, sugar, milk and the raw material for instant coffee supplied by way of raw material chute 114, and hot water supplied from hot water supply tube 107B are selectively received by mixing bowl 115, in accordance with a serving command for a coffee beverage, and supplied to cup C through nozzle 115A. Cups C stored in cup supply apparatus 116 are supplied to cup receiver 117 and placed at the position to receive cold water discharged from nozzle 104A (in water supply unit 100A), the coffee beverage discharged from nozzle 115A and, in addition, syrup supplied from a syrup canister, not shown. Cold water, the coffee beverage or syrup is thus received by cup C. Steam produced in beverage extraction unit 100C and mixing bowl 115 is exhaled through steam exhaust tubes 119A and 119B, respectively, by the help of blower fan 120 provided at their distal ends, in order to prevent outlets 109A, 111A, 112A and 113A of canisters 109, 111, 112 and 113, respectively, from being choked by steam.
Beverage extraction unit 100C is provided with cylinder 20 for agitating the mixture of the raw material supplied from regular coffee canister 109 with hot water supplied from hot water supply tube 107A and discharging the mixture downward, paper filter 21 for filtering the mixture discharged from cylinder 20, beverage receiver 22 for receiving regular coffee extracted by filtration with paper filter 21 and supplying it to beverage supply tube 22C, air pump 5 for supplying compressed air to cylinder 20 and beverage receiver 22 through upper air valve 50 and lower air valve 51, respectively, and heater block 121 for heating cylinder 20 to prevent lowering of the temperature of hot mixture in cylinder 20.
Cylinder 20 is supported by a guide rail, not shown, to be movable up and down. Paper filter 21 is located under cylinder 20 to receive the mixture prepared therein. Cylinder 20 consists of receiving chamber 20a for receiving the raw material and hot water, and extraction chamber 20b for extracting the beverage from the mixture of the raw material and hot water received in receiving chamber 20a. Receiving chamber 20a and extraction chamber 20b are communicated with each other through a conduit (not shown) which is opened and closed by a valve (not shown).
Upper air valve 50 and lower air valve 51 are each opened and closed according to the state of extraction in beverage extraction unit 100C. In the agitation process, upper air valve 50 is closed and lower air valve 51 is opened so as to supply compressed air from air pump 5 to beverage receiver 22. In the extraction process, upper air valve 50 is opened and lower air valve 51 is closed so as to supply compressed air to the upper part of extraction chamber 20b from air pump 5.
Heater block 121 is provided with heater 121A inside. Heater block 121 mounted on the outer surface of extraction chamber 20b serves to heat cylinder 20, thereby the temperature of hot water within cylinder 20 is prevented from lowering due to transfer of the heat to cylinder 20 from the hot water.
The operation of preparing regular coffee in the beverage preparation unit above will be explained. When a command for serving regular coffee with sugar and mild is given, cylinder 20 is descended, being driven by a motor not shown, so that the bottom of extraction chamber 20b comes into contact with beverage receiver 22, having paper filter 21 interposed between them. Then, the raw material supplied from regular coffee canister 109 through outlet 109A is received by raw material chute 110 and thrown into receiving chamber 20a in cylinder 20, having the conduit therein opened. At the same time, hot water supply valve 106A is opened to supply hot water stored in hot water tank 105 to receiving chamber 20a in cylinder 20 through hot water supply tube 107A heated by heater block 108. The raw material and hot water received in receiving chamber 20a is supplied to extraction chamber 20b, because the conduit between them is opened. The mixture in extraction chamber 20b does not flow out to beverage supply tube 22C because a valve (not shown) provided on beverage supply tube 22C just below beverage receiver 22 is closed. At the same time, blower fan 120 operates to exhale steam generated in receiving chamber 20a to the atmosphere through steam exhaust tube 119A.
Then, upper air valve 50 is closed, lower air valve 51 is opened and air pump 5 is driven, thereby compressed air is supplied to beverage receiver 22. Compressed air supplied to beverage receiver 22 passes through paper filter 21, flows into extraction chamber 20b and passes through the mixture within extraction chamber 20b to form bubbles, thus the flow of the bubbles agitates the mixture.
After a predetermined time for agitation process elapses, air pump 5 is stopped, and the conduit in cylinder 20 is closed by displacement of the valve (not shown) attached to the conduit. Thereafter, the valve on beverage supply tube 22C is opened, upper air valve 50 is opened, lower air valve 51 is closed and air pump 5 is driven, thereby compressed air is supplied to the space in the upper part of extraction chamber 20b. Thereby, the mixture of the raw material with hot water in extraction chamber 20b is pressed down by the compressed air in the upper space thereof, discharged therefrom, and filtered by paper filter 21 to produce regular coffee, which is transported through beverage supply tube 22C to mixing bowl 115.
Meanwhile, sugar and milk are discharged from outlet 111A of sugar canister 111 and outlet 113A of milk canister 113A, respectively, and supplied to mixing bowl 115 by way of raw material chute 114 so as to form regular coffee with sugar in mixing bowl 115. Steam generated then in mixing bowl 115 is exhaled through steam exhaust tube 119B out of blower fan 120 to the atmosphere. Regular coffee with sugar and milk prepared in mixing bowl 115 is poured into cup C from nozzle 115A.
In the beverage preparation apparatus, cylinder 20 is heated by heater block 121 mounted on the outer surface of extraction chamber 20b, thereby transfer of heat from the hot water in extraction chamber 20b during agitation and extraction is retarded, facilitating supply of a hot beverage by extraction.
Meanwhile, another conventional beverage serving apparatus prevented from temperature lowering of the extracted beverage is disclosed, for example, in Japanese Patent Application Laid Open No. Hei5-197878. In the beverage serving apparatus, the main components such as cylinder and beverage receiver are contained in a case, and air in the case is heated by a heater to keep the main parts hot.
In the conventional beverage serving apparatus shown in FIG. 1, however, heat is radiated from the outer surface of extraction chamber despite the extraction chamber 20b is heated locally by a heater block, thus it is difficult to serve a hot beverage by extraction.
Further, a blower fan is used in the apparatus both for exhaust from the receiving chamber for mixing the raw material with hot water and for exhaust from the mixing bowl for addition of milk and sugar to the beverage, in common. This means that the exhaust from the mixing bowl is accompanied by the exhaust from the beverage extraction unit when serving another kind of beverage is requested, enhancing the aforesaid heat radiation and, thus, making it difficult to serve a hot beverage. This is also the case for the apparatus in Japanese Patent Application Laid Open No. Hei5-197878.